"Silent Night" (German: "Stille Nacht, heilige Nacht") is a popular Christmas carol. The original lyrics of the song "Stille Nacht" were written in Oberndorf bei Salzburg, Austria, by the priest Father Joseph Mohr and the melody was composed by the Austrian headmaster Franz Xaver Gruber. In 1859, John Freeman Young (second Bishop, Episcopal Diocese of Florida) published the English translation that is most frequently sung today. The version of the melody that is generally sung today differs slightly (particularly in the final strain) from Gruber's original, which was a sprightly, dance-like tune in 6/8 time, as opposed to the slow, meditative lullaby version generally sung today. Today, the lyrics and melody are in the public domain.
A version recorded by Bing Crosby is one of the fewer than thirty all-time singles to have sold 10 million (or more) copies worldwide.
lots more : http://en.wikipedia.org/wiki/Silent_Night